Lifting Analysis DR.AYESHA BHATTI

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1 Lifting Analysis DR.AYESHA BHATTI BSPT, PPDPT.PPTA

2 OBJECTIVES Use biomechanical principles when analyzing a lift. Critically analyze three lifting techniques. Develop an abatement protocol to prevent commonly encountered lift-related injuries.

3 Definitions: Low back. Pain in the lumbar spine and its anterior/posterior components. Iliosacral area may also be included. Pain. Subjective,.. often nocuous response to stressors that overwhelm the tissues being exposed. Prevention. The use of accepted scientific principles in the obviation of risk factors that may predispose an individual to injury.

4 Lifting Essential part of everyday life Correlation with variety of Musculoskeletal injuries especially back pain High Financial cost Workplace education and design by medical professionals as well as Ergonomists

5 The Biomechanics Of Lifting Stress Compression, shear, and torsion/tension Training the workers to lift in a biomechanically safe manner

9 Stoop lift Maneuver that typically requires maximal flexion of the trunk and as near to terminal extension of the knees (without locking) as possible.

11 Squat Lift It requires knee flexion >90 degrees and trunk flexion <30 degrees

13 Semi-Squat Lift The semi-squat lift shares characteristics of the stoop and squat Semi-squat uses a posture calling for knee flexion >45 degrees and trunk flexion at approximately same angulation Greater anterior tilt of the pelvis with this approach in comparison with the other lifts, promoting a lumbar Lordosis

15 Freestyle Lift lift resembles in most respects the semi-squat but can differ from person to person It is this variability that makes it difficult to examine during controlled studies

16 Trunk Kinetic Lift The trunk kinetic lift is characterized by a sudden extensor moment of the knees before the lift

17 Load Kinetic Lift The load kinetic lift requires a closer approximation of the load to the body just before the initial acceleration moment. This lift, too, is seen as a variation of the three more standard lifts

18 Critique Of Lifting Techniques A) Biomechanical Analysis: Comparison of various lifting techniques At L5/S1 lumbar moment and compressive forces were equal for the stoop and squat in one study One study indicated less forces in stoop lift as compared to squat lift

19 It is generally accepted that the closer the load is placed to the body, the more significantly diminished the resultant compressive forces to the lumbar spine Employed more effectively in the semisquat lift (load between the feet and knees) than with the stoop or squat lift

20 Shear forces are significantly higher (in some cases 180%) during the squat lift. Low back loading was significantly higher during squat lifting than with the stoop lift when lifting from the floor

21 Foot placement, is contingent on the size of the load: If the container is too wide (large) to If the container is too wide (large) to allow for proper foot placement (greater than shoulder width approximately 30 cm [12 in]), then the ideal lift would be the stoop, since it would result in less compressive forces.

22 Soft tissue compliance supraspinous and interspinous ligaments more effectively countered the lumbar moment (be it as a result of shear or compressive forces) during the stoop rather that the squat and semi-squat lifts Activation muscle modify shear forces.(proper lordotic posture)

24 Erector Spinae Muscle (illiocostalis, longissmus and spinalis)

26 B) Physiologic Response Oxygen uptake/consumption, %VO2 max, the gold standard of energy expenditure, was found to be greater with the squat lift than with the stoop Increased muscular effort in Squat and semi squat as compared to stoop lift Tendency to Switch from the squat and semi-squat to the stoop lift because of the increased energy demands of the squat lifts

27 C) Perceived Exertion Rating of perceived exertion (RPE), a subjective measure, rates the individual s own awareness of the effort required to perform a particular activity 90% of the subjects rated the squat lift as more fatiguing than the stoop lift

29 Increased angulation of the lumbar spine in stoop lift through flexion causes both increased compression and shear forces to the intervertebral disc, it would make to prescribe the semi-squat or squat technique when an individual is required to lift heavy objects on an occasional basis. In addition, the squat requires more energy expenditure, thus making the semisquat the preferred lift for occasional heavy effort (four work cycles per minute).

30 The semi-squat lift allows for closer The semi-squat lift allows for closer placement of the load to the body, thus creating a smaller moment arm and less compressive force. The preferred lift between the semi-squat lift and the pure squat would be the semi-squat.

31 Another more subjective measure of individual lifting tolerances uses maximum allowable weight (MAW) as a determining factor. Maximum allowable weight (MAW) measure of individual lifting tolerances researchers reported that 17 females selected a MAW 20.5% greater for the stoop than for the squat lift. When comparing the squat and semi-squat exclusively, subjects chose a greater 25.4% MAW, preferring the semi squat over the squat.

32 Response of an individual experiencing low back pain and what adjustments are made to negotiate a lift from floor to waist Asymptomatic group showed no preference between the squat or stoop lift but that more than two thirds of those with back pain (symptomatic group) had adopted the squat or semisquat as their preferred lift

33 To continue: preferred techniques

Posture. Kinesiology RHS 341 Lecture 10 Dr. Einas Al-Eisa

Posture. Kinesiology RHS 341 Lecture 10 Dr. Einas Al-Eisa Posture Kinesiology RHS 341 Lecture 10 Dr. Einas Al-Eisa Posture = body alignment = the relative arrangement of parts of the body Changes with the positions and movements of the body throughout the day